/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements. See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.inlong.sort.filesystem.stream;

import org.apache.inlong.sort.base.dirty.DirtyOptions;
import org.apache.inlong.sort.base.dirty.sink.DirtySink;

import org.apache.flink.core.fs.Path;
import org.apache.flink.runtime.state.StateInitializationContext;
import org.apache.flink.runtime.state.StateSnapshotContext;
import org.apache.flink.streaming.api.functions.sink.filesystem.StreamingFileSink;
import org.apache.flink.streaming.runtime.streamrecord.StreamRecord;
import org.apache.flink.table.filesystem.stream.PartitionCommitInfo;

import javax.annotation.Nullable;

import java.util.ArrayList;
import java.util.HashSet;
import java.util.NavigableMap;
import java.util.Set;
import java.util.TreeMap;

/**
 * Writer for emitting {@link PartitionCommitInfo} to downstream.
 */
public class StreamingFileWriter<IN> extends AbstractStreamingWriter<IN, PartitionCommitInfo> {

    private static final long serialVersionUID = 2L;

    private transient Set<String> currentNewPartitions;
    private transient TreeMap<Long, Set<String>> newPartitions;
    private transient Set<String> committablePartitions;

    public StreamingFileWriter(
            long bucketCheckInterval,
            StreamingFileSink.BucketsBuilder<IN, String, ? extends StreamingFileSink.BucketsBuilder<IN, String, ?>> bucketsBuilder,
            String inlongMetric, String inlongAudit,
            DirtyOptions dirtyOptions,
            @Nullable DirtySink<Object> dirtySink) {
        super(bucketCheckInterval, bucketsBuilder, inlongMetric, inlongAudit, dirtyOptions, dirtySink);
    }

    @Override
    public void initializeState(StateInitializationContext context) throws Exception {
        currentNewPartitions = new HashSet<>();
        newPartitions = new TreeMap<>();
        committablePartitions = new HashSet<>();
        super.initializeState(context);
    }

    @Override
    protected void partitionCreated(String partition) {
        currentNewPartitions.add(partition);
    }

    @Override
    protected void partitionInactive(String partition) {
        committablePartitions.add(partition);
    }

    @Override
    protected void onPartFileOpened(String s, Path newPath) {
    }

    @Override
    public void snapshotState(StateSnapshotContext context) throws Exception {
        super.snapshotState(context);
        newPartitions.put(context.getCheckpointId(), new HashSet<>(currentNewPartitions));
        currentNewPartitions.clear();
    }

    @Override
    protected void commitUpToCheckpoint(long checkpointId) throws Exception {
        super.commitUpToCheckpoint(checkpointId);

        NavigableMap<Long, Set<String>> headPartitions =
                this.newPartitions.headMap(checkpointId, true);
        Set<String> partitions = new HashSet<>(committablePartitions);
        committablePartitions.clear();
        headPartitions.values().forEach(partitions::addAll);
        headPartitions.clear();

        output.collect(
                new StreamRecord<>(
                        new PartitionCommitInfo(
                                checkpointId,
                                getRuntimeContext().getIndexOfThisSubtask(),
                                getRuntimeContext().getNumberOfParallelSubtasks(),
                                new ArrayList<>(partitions))));
    }
}
